Contact for electric furnaces.



FREDERICK T. SNYDEB,.0'F 0AX- PARK, ILLINOIS.

CONTACT FOB ELECTRIC FURNACES.

Specieation o1 Letters 'Patenti Patented J une 23, 11914.

Application ld October 28, 1912. Serial N o. 728,088.

`To all 'whom it may concern.'

Be it known that I, FREDERICK T. Si-iYDnR, citizen of the United States, residing at Oak Park, in the county ofy Coolr and State, of Illinois, have invented a certain new and Y full` clear, concise, and exact description.

My invention relates to electric furnaces, and more particularly to the bottom electrode or contact-holder of an electric furnace. Its object is to provide an elect-rode or coiitact-liolder which can be readily secured to the exterior casing or shell of the furnace, which will provide good electrical connection between the electrode and the ground connection therefor and suitable iiieans for cooling the electrode.

In a well known type of electric furnace, the negative electrode extends vertically through the cover of the furnace, the bottom of the furnace being provided with an opening for receiving the bottom or positive electrode or contact, which latter may consist in part of the molten material treated in the furnace, the lower end of the bottom` electrode or Contact extending through the wall of the furnace and being held in place and cooled in soine suitable manner.

It is the object of my invention toprovide improved means for cooling the contact or bottoni electrode of an electric fui'- nace of the type described'.

My invention may be more readily understood by reference to .the accompanying drawings, in which- Figure l is a central, vertical section of an electric furnace embodying my invention; Fig. 2 is an enlarged elevation, partly iii section, of the Contact shown in Fig. 1; Fig. 3 is an elevation at right angles to the elevation shown in Fig. 2; and Fig. 4 is a top plan view of the Contact.

Similar reference characters refer to similar parts throughout the several views.

Referring to the drawings, the lower wall or bottom of the furnace Vis of the usual coiistruction, comprising masonry 1 inclosed by a metallic shell or casing 2, preferably of copper, Vsaid wall or bottom of the furnace being provided with an opening for the reception of the contact 3. Mounted upon the bottom of the furnace about said opening and detachably secured to the shell 2 is the contactholder 4. Said contact-holder and contact are preferably cast in one integral piece. VThe contact-holder is preferably a metallic-block havin six rectangular faces. At its four corners ie block 4 is provided with vertical holes 5 for the reception of bolts 6, whereby the -holder may bebolted to the Wall of the furnaceand, by tightening the nuts 7,- may be drawn into olose contact with the shell 2. The block 4 and the contact propel'V 3 isV preferably a steel casting. Byboltingthe holder 4 to the shell 2, good electric contact is provided between said shell and contact-holder. Heretofore it has been customary to ground the holder' by a flexible conductor secured thereto. In the preferred embodiment of my invention, as shown in the drawings, the flexible ground connection 8 is clamped by the plate 9, or in any suitable manner, to the shell 2 near the circumference thereof. The flexible conductor 10 is thus connected to the shell 2 at a readily accessible portion thereof. When the electrode is in position the ground connection for the material vin the furnace extends through the contact 3, the holder 4, the metallic shell 2 and the flexible conductor 8.

The block 4 is formed with one or more water chambers l0, through which water is circulated for cooling the block 4 and contact 3. Said chambers l() are of circular cross-section and the circular walls thereof are spirally grooved so as to give a whirling motion to the water as it is circulated through the chambers, and also to increase the inner surface of the chamber with which the water comes vinto rubbing con` tact. Since the transfer conductivity of heat from metal to water varies directly as the velocity of the water, it is desirable that the velocity of the water be as high.as practicable. By this is not meant merely the velocity of the water as it passes through the inlet port or out of the outlet port. Such rapid circulation ofthe water would be ineflicient and costly. My invention, on the contrary, is designed to give to a comparatively slow flowing stream of water a relatively high rubbing 'velocity with the walls of the water-chamber and thus to get the most efficient cooling from a minimum volume of water. The water-chambers 10 are preferably straight holesextending from one side to the other of the block 4. These holes are cored through said block, and the outer ends thereof are preferably of reduced diameter and are threaded to receive the inlet pipes 11, l1 and the outlet pipes 12, 12. Said pipes are thus connected directly to the block 4 without the provision of any intermediate coupling member.

My invention thus provides a sim le, lcheap and efficient water-cooled bottom-e ectrode or contact.

I claim 1. A contact-,holder havin ber lprovided with means gir imparting a whirling motion to Water circulated through said chamber.

2. A contactholder having a spirally grooved water-chamber.

3. A contact-holder comprising a metallic block provided with a hole extendin therethrough constitutin a water-cham er, the block being threade at the opposite ends of said hole to receive a correspondingly a water-chamthreaded inlet and an outlet ipe, respec'- tively, and the main portion /o said chamber being' provided with a continuous groove extending spirally about said chamber.

4. In an electric furnace, a contact having my name this 26th day of October, A. D.

FREDERICK T. SNYDER.

Witnesses:

ALFRED II. Moonn, MCCLELLAND YOUNG. 

